Another boat heater question - backdrafts!

[HinewaisMan]

Have an old Fab-All diesel heater, similar to the Dickinsons. Not often used in Australia, got a good workout last winter in the UK.

Has a basic cowl, as much to stop rain getting in as letting fumes out.

Most of the time it worked great, toasty down below, but with certain wind directions over the deck, it would backdraft and blow out. Not only did this fill the boat with a mixture of smoke and vapourised diesel, it made me very unpopular downwind until the fuel load had evaporated off.

Back with the great god Google, there seems to be three possible alternatives solutions and all work out about the same price.

* The first to install a barometric damper into the flue inside the boat;
* The second is replace the cowl with an "H" shaped cowl cap touted as "Best for preventing backdraft, for rough weather" and,
* The third is to use a Clover Leaf cowl "Traditional style mariner cap".

I must admit I lean towards the damper, but only because it is fitted and stays in situ without the need to store a awkward sized and shaped cowl when the deck chimney is taken down. However, past experience suggests that if I lean towards a solution, it may not be the best.

So I turn to my peers and ask for your advice. Is it a balance of pros and cons, a mix of two, or is one solution by far the best?

Thanks

Peter

 

[pvb]

Had a similar problem years ago with an ancient domestic oil-fired boiler. An H-shaped cowl cured it - not pretty though.

 

[Blueboatman]

I have yet to make a H cowl. And/or quite fancy a rotating spinning one as you see on domestic chimneys

For now, on a Taylors dripfeed diesel, I have used for three whole winters, an extended, 1.2m double walled straight flue that simply gets the flue top into clear air. the double walling prevents burns and keeps heat to the top thus drawing exhaust up better, good for 50 knots in a marina.. Gets a dunk in the ocean on a string then wrapped in a binliner and put away. Started life as the balanced flue for a gas house boiler I reckon, perfect..

I think the H one is the way to go ( without proof!)

These guys have bits http://www.elyboatchandlers.com/wall-mounted-heaters, to give an idea of what is available but you prob know what is around already?

 

[elton]

Slightly off-topic, but a nice looking house boat on the end of my pontoon was all but destroyed last winter when burning embers were blown out of the stove by a backdraft during the night. The two occupants were very lucky to escape with their lives.

 

[Blueboatman]

Fit mesh screen?

 

[cryan]

H-shapes are basic and functional which is usually the best choice. Popular on a lot of old craft from pleasure boats to trawlers.

 

[NornaBiron]

Has your heater got an air intake on deck and a separate exhaust? I have used many Reflex drip fired diesel heaters on trawlers. If they relied on cabin air and if the cabin door closed, they always backfired and made one hell of a mess. The one I have now has a separate air intake and has no problems. This is the exhaust we use:

http://www.toplicht.de/en/shop/ofen...aylors-abgashauben/abgashaube-taylors-htd5166